1. Technical Field
This invention relates generally to document reproduction apparatus such as copiers, printers, and the like.
2. Background Art
Machine control systems for document reproduction apparatus are known in many forms, such as for example mechanical systems of levers, gears, cams, rollers, and/or belts to transmit signals required to sequence or time system functions. Mechanical systems can be noisy, inefficient, expensive, bulky, limited in transmission distance, and slow. Pneumatic and hydraulic systems which use hoses to transmit signals have the advantage of permitting functions spaced farther apart, but they still share many of the disadvantages of mechanical machine control systems.
More modern electrical or electronic machine control systems use various sensors, switches, motors, solenoids, and clutches interconnected by wires or other electrically conductive means. Electrical or electronic systems are generally quiet, cost effective, fast, and compact; and can control widely spaced apart functions. However, the wires conducting the signals take up space and can be transmitters and receivers of electromagnetic interference (EMI).
One of the latest advances in machine control is the use of electro-optical systems which employ fiber optic light conductors to transmit signals to and from the functional elements in the system. While light conductors are very fast, transmit large amounts of control information, and are immune to electromagnetic interference, their application is limited because the conductors are costly and require routing in areas where space may be at a premium.